Blue Lake, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

674
FXUS65 KPSR 071149
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
449 AM MST Wed May 7 2025

.UPDATE...Updated 12z Aviation Discussion.

&&

.SYNOPSIS...
The low pressure system that has brought periods of rainfall
since Sunday will gradually exit the region today as high pressure
begins to filter in from the west. Some lingering shower chances
will remain through this afternoon mainly west of Phoenix and over
the Arizona higher terrain, while a warming trend will also
commence. As high pressure strengthens over the region Thursday
into the weekend, temperatures will quickly trend higher. Expect
high temperatures back into the normal range Thursday before
peaking this weekend at around 105 degrees. The hot temperatures
Friday and over the weekend will bring a Moderate HeatRisk across
the region before temperatures begin cooling down early next week.

&&

.DISCUSSION...
A fairly vigorous vort max supported by an upper level jet max
brought moderate to locally heavy rainfall across portions of
eastern Riverside County into La Paz County during the evening
hours with the activity gradually winding down since midnight.
Most of the instability has already been exhausted and the forcing
from the vort max and jet streak is quickly weakening. However,
this area of rain should continue to bring light rainfall to
locations west of Phoenix through around mid morning with an
additional 0.25" of rainfall in some locations. The vort max is
forecast to shift into southern Arizona during the afternoon hours
with any lingering forced ascent shifting over southeast Arizona
into the higher terrain east and northeast of the Phoenix area.
This should allow for some isolated to scattered showers in these
area this afternoon as indicated by the Hi-res CAMs, but
additional rainfall amounts should be fairly light.

Forecast concern then turns toward the rapid warming expected
through the rest of the week with Moderate HeatRisk developing by
Friday to even some localized areas of Major HeatRisk possible
over the weekend. Once this upper level trough finally begins to
exit later today into Thursday, upper level ridging is forecast to
quickly overspread the region with H5 heights rising to around
582dm on Thursday and 585dm on Friday. This will quickly push
daytime highs into the lower 90s on Thursday and to around 100
degrees on Friday. The core of the upper level ridge is expected
to be centered over the Great Basin and northern Arizona, but our
area should still see H5 heights reach into the 90th percentile of
climatology for this time of year. Both the GEFS and EPS show H5
heights peaking between 585-587dm on Saturday will little change
into Sunday. NBM guidance for Saturday and Sunday show highs
anywhere from 102-106 degrees across the Phoenix area to 104-108
degrees across the lower deserts of southwest Arizona and
southeast California. Even though these temperatures will fail to
reach into record territory, they will still be pushing near 15
degrees above normal. Widespread areas of Moderate HeatRisk are
expected Friday through Sunday with some areas of Major HeatRisk
now appearing across the lower deserts mainly on Saturday. If
guidance pushes temperatures any higher, an Extreme Heat
Watch/Warning may have to be issued for some locations this
weekend.

Ensembles still heavily favor a large Pacific trough entering the
Pacific Northwest Sunday into Monday, while likely beginning to
influence our region to some degree by Monday. NBM temperature
guidance does show higher spread during the first half of next
week, but there is a clear downtrend in temperatures expected with
highs likely falling back into the upper 90s/100 degrees on
Monday and into the normal range as early as Tuesday. This trough
should eventually swing through our region during the middle part
of next week bringing temperatures a bit below normal by
Wednesday. Aside from the cooling trend with this trough, we can
also expect some breezy to locally windy conditions and periods of
mid to high clouds.

&&

.AVIATION...Updated at 0545Z.

South Central Arizona including KPHX, KIWA, KSDL, KDVT:
The primary aviation concern through the TAF period will be
uncertainty in VCSH/SHRA conditions developing Wednesday morning
and continuing into the afternoon hours. The weather disturbance
responsible for showers and thunderstorms across the Colorado
River Valley and surrounding areas will rotate through South
Central Arizona over the next 24 hours, though confidence in
VCSH/SHRA conditions is too low at any of the terminals for
inclusion at this time. Most activity is expected to die out
across Northwestern Maricopa County before moving overhead. The
most likely impact of this disturbance will be a period of SCT-BKN
clouds down to 6-7 kft AGL this morning. Winds will begin to
follow more typical diurnal trends, with speeds generally
remaining AOB 10 kts, however, depending on how close SHRA
activity gets to the terminals, stronger NW winds may temporarily
materialize early this morning. Skies will clear going into the
evening and overnight hours, with typical overnight easterly to
southeasterly component winds developing during the overnight
hours.

Southeast California/Southwest Arizona including KIPL and KBLH:
Some light shower activity continues to persist near KBLH, but
elected to keep any VCSH prevailing conditions going through the
early morning hours. Winds at KBLH should continue to prevail out
of the northerly direction through most of the period. At KIPL,
light and VRB winds expected to strengthen out of the NNE late
morning before weaken to light and VRB again this evening. SKC
skies will return Wednesday late afternoon/evening at both
terminals.

&&

.FIRE WEATHER...
Isolated showers will still be possible today mainly over the
Arizona higher terrain as temperatures begin to warm up. High
pressure will spread over the region by Thursday with
temperatures warming further before well above normal temperatures
with highs topping 100 degrees are expected Friday and through
the weekend. MinRHs will trend down over the next several days
with values ranging around 30-40% today, 15-25% Thursday, and
10-15% starting Friday. Winds will overall remain light, mostly
at or below 10 mph, through the next couple of days.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&

$$

DISCUSSION...Kuhlman
AVIATION...Young/Whittock
FIRE WEATHER...Kuhlman